This invention relates to central nervous system function.
Although disorders such as Parkinson""s disease, attention deficit disorder, schizophrenia, substance abuse, and mood and anxiety disorders generally involve imbalances in central nervous system functioning, the underlying neurological mechanisms of these diseases are poorly understood, with a corresponding dearth of suitable diagnostic methods and pharmacological therapies.
Blood oxygen level dependent functional magnetic resonance imaging (BOLD fMRI), near infrared optical imaging, and emission tomography methods have been used to assess cortical function. The BOLD fMRI method for studying stimulus-induced brain activity changes uses activity-dependent increases in local blood flow, with resultant decreases in the local deoxyhemoglobin concentration as a surrogate marker for increased local neuronal activity, and has been used to analyze visual cortical function. For example, visual stimulus-induced occipital cortical BOLD signal change has been shown to be dependent on gender and age, and to be influenced by disease processes such as schizophrenia. In addition, stimulus-induced occipital cortical activation is altered during the administration of exogenous substances, such as amphetamine, cocaine, and ethanol.
It would be useful to efficiently diagnose disorders of the central nervous system, and to evaluate effective pharmacological therapies for such disorders.
The invention features methods of assessing and diagnosing central nervous system function in a human subject.
In one aspect, the invention provides a method of assessing central nervous system function in a human subject by subjecting the subject to a blue light stimulus and performing cortical imaging, for example, functional magnetic resonance imaging, near infrared optical imaging, or emission tomography, on the subject. In a preferred embodiment, the method further includes treating the subject with a therapeutic agent for affecting central nervous system dopamine function, to assess the efficacy of the agent.
In another aspect, the invention provides a method of diagnosing a central nervous system disorder in a human subject by subjecting the subject to a blue light stimulus and performing cortical imaging, for example, functional magnetic resonance imaging, near infrared optical imaging, or emission tomography, on the subject. In preferred embodiments, the central nervous system disorder includes a disorder of central nervous system dopamine function, e.g., schizophrenia, Parkinson""s disease, attention deficit hyperactivity disorder, substance abuse disorders, or mood and anxiety disorders (such as major depression or bipolar disorder).
In a preferred embodiment of both aspects of the invention, the blue light stimulus is compared to a light stimulus of a different color (e.g., red or green).
The methods, as are described in detail below, offer a wide range of advantages and applications. Other features and advantages of the invention will be apparent from the following detailed description.
By xe2x80x9ccentral nervous system functionxe2x80x9d is meant any process responsible for, or mediating, affect, mood, behavior, cognition, perception, sensation, brain activity, or motor behavior.
By xe2x80x9ccentral nervous system disorderxe2x80x9d is meant any disease, pathological condition, or disorder, either acquired or genetically inherited, that adversely affects central nervous system function.
By xe2x80x9cblue light stimulusxe2x80x9d is meant a light stimulus of about wavelength 430-500 nm.
By xe2x80x9cred light stimulusxe2x80x9d is meant a light stimulus of about wavelength 640-700 nm.
By xe2x80x9ctreatingxe2x80x9d is meant the medical management of a patient with the intent that a cure, amelioration, or prevention of a dependency or a relapse or associated disease, pathological condition, or disorder will result. This term includes active treatment, that is, treatment directed specifically toward improvement of the dependency or associated cure of a disease, pathological condition, or disorder, and also includes causal treatment, that is, treatment directed toward removal of the cause of the dependency or associated disease, pathological condition, or disorder. In addition, this term includes palliative treatment, that is, treatment designed for the relief of symptoms rather than the curing of the dependency, disease, pathological condition, or disorder; preventive treatment, that is, treatment directed to prevention of the dependency or associated disease, pathological condition, or disorder; and supportive treatment, that is, treatment employed to supplement another specific therapy directed toward the improvement of the dependency or associated disease, pathological condition, or disorder. The term xe2x80x9ctreatingxe2x80x9d also includes symptomatic treatment, that is, treatment directed toward constitutional symptoms of the dependency or an associated disease, pathological condition, or disorder.
By xe2x80x9ctherapeutic agentxe2x80x9d is meant a compound that is known to, or is proposed to, affect central nervous system neurotransmitter function. In general, a therapeutic agent is one that is used for treating neurologic, psychiatric, or substance abuse disorders.
By xe2x80x9caffectingxe2x80x9d is meant changing, either by decreasing or by increasing.